INFLUENCE OF THE REINFORCEMENT ADDITIONS ON THE CREEP STRENGTH OF DISPERSION-STRENGTHENED ALUMINUM-ALLOYS

A comparitive study of creep behaviour was conducted on eight differen t aluminium alloys which are strengthened by carbide and oxide dispers oids with three different volume fractions (C002, C101, C102). The mat rix materials are AISi20, AlSi20Fe5, AlMgSi1, AlSi12Fe5, AlMg1, AlMg2, AlMg4 and AlCuMg1. The dispersoids were added to the matrix material powder and processed by mechanical alloying. Creep tests were carried out on cylindrical specimens at 300 degrees C and 400 degrees C up to fracture. These products were fabricated by cold isostatic pressing (C IP) followed by hot extrusion to improve its mechanical properties. Th e applied stress was chosen to have a fracture life ranging from 0.1 t o 3000 hours. It was concluded that the adding of 1% carbon and 2% oxy gen as a dispersioid materials in the aluminium alloy matrix has a gre at effect on the creep strength in comparison with the addition of the alloying elements such as Si, Mg, Cu and Fe in high percentages up to 20%.